Buttonhole-sewing machine



H. C. SEARLE.

BUTTONHOLE SEWING MACHINE.

APPLICATION FILED Aue.15. x919.

1,388,331 3 te Aug- 23, 1921'.

UNITED STATES PATENT *oFFlcE- HENRY C. SEARLE, OF ROXBURY, MASSACHUSETTS, ASSIGNOR TO IINI'IED SHOE MACHINERY CORPORATION, OF PATERSON, NEW JERSEY, I A CORPORATION OF NEW JERSEY.

BUTTONHOLE-SEWING MACHINE. I

Specification of Letters Patent. Patented A 23; 1921.

Application filed August 15, 1919. Serial No. 317,655.

T all whom it may concern:

Beit' known that I, HnNnY C. SEARLE, a citizen of the United States, residing at WVest Roxbury, in the county of Suffolk and State of Massachusetts, have invented certain new anduseful Improvementsin But- 7 tonhole-Sewing Machines; and I do hereby declare the following to be a full, clear, and

exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates particularly to that type of buttonhole sewing machine inwhich the stitch-forming mechanism comprises a.

vertically reciprocating upper needle which penetrates the 'work a short distance from the buttonhole slit, a looper which takes a loop of the upper needle thread and holds it below the work in position for the passage up therethrough of the under needle and an oscillating curved under needle which carries a loop of under thread up through the loop held by the looperand presents it in position for the passage down therethrough of the upper needle.

Machines of this type are usually so constructed that the under needle passes up through the previously cut buttonhole slit throughout the sewing of the buttonholerso that the needle is not subjected to the strains incident to piercing the work. Machines of this type may also be utilized in sewing but- A tonholes such as fly-bar buttonholes which require the under, needle to penetrate the work at the beginning and at the end of the sewing. In machines adapted for this class Missed stitches and broken under needles frequently result. 7

The present invention is designed to remedy the defect outlined above and to render the operation of the stitch-forming mechanism certain and reliable. This is accomplished by providing the under needle with a surface which is arranged to uniformly press or crowd the point of the needle inward or toward the axis of oscillation of the needle as it is forced through the work. Such a surface may conveniently be provided by locating the extremity of the needle point inside the axis of the needle so that the inclined surface from the point to the outer side of the needle will have a greater rise and therefore a greater camming action or tendency to deflect the needle than the opposed surface on the inside of the needle. Whenever the needle thusformed penetrates the work its point will be pressed inward so that the pressure tending to deflect the needle will uniformly be in the same direction and in the direction which the needle is best adapted to withstand and in which slight deflection of the needle will not materially affect its cooperation with the upper needle. Since any deflection which may result will always be in the same direction the proper preliminary adjustment of the parts may readilybe made to compensate for whatever deflection is likely to oc: our.

The pressing inward of the point of the needle also insures a continued pressure by the work on the-outside of the needle during its passage throughvthe work so that; the work forms in effect a needle guide which uniformly bears upon the outside of the needle and supports and guides it in the proper path to cooperate with the upper needle. 7 v

The invention is illustrated in the accompanying drawing-in which Figure 1 :is a sectional elevation of so muchof a buttonhole sewing machine as is necessary to illustrate the application of the invention thereto, and Fig. 2 is an enlarged view, of the under needle. I

In the drawing the invention is shown embodied in a buttonhole sewing machine having the general construction and mode of operationof the machine shown and described in the patent toHill, 1,063,880, June 3, 1913. The stitch-forming mechanism of this machine comprises a vertically recipro to sew fly-bar buttonholes the cams which control the rotary movement of'the stitch forming mechanism and the movements of the work clamp lengthwise and transversely of the buttonhole are so shaped that the initial and final stitches of the seam are formed in the work in line with the bar end of the buttonhole slit, the final stitches over lying the initial stitches.

In embodying the preferred form of the invention in the above machine, the pointed end of the under needle is so formed that the pointof the needle is inside the medial line or longitudinal axis of the needle. The inclined surface 10 extending from the point to the outside of the needle has there fore a greater rise than the inclined surface 12 extending from the point to the inner side of the needle, and the surface 10 will act by engagement with the work as the .point of the needle penetrates the work to press the needle point inward toward the axis about which the needle oscillates. This will tend to bend or deflect the needle inward, and in case the stock is of a charac ter to offer materialres stanceto the pas sage of the needle, will Slightly deflect the needle so that the pressure on the outer side of the needle will be maintained during the upward stroke of the needle and. will tendto guide and support it in its proper path dle tending to deflect it is therefore uni of movement with relation to the upper:

needle. Any pressure or strain on the neeformly' in the same inward direction, and the parts may be adjusted to compensate for any variations inthe deflection of the 1166(ll6 '\VhiCl1 are likely to occur. Outward strains which are likely to break the needle or to so deflect it that the upper needle will not pass through its loop are thus avoided and the proper cooperation of the stitch-forming devices insured.

While it is preferred to employ the specific construction shown and described, it

will be understood that this is not essential to the broader features of the invention and that the surface for pressing the needle inward may be otherwise located or formed. \{Vhat is claimed is: 1. A buttonhole sewing machine; having, in combination,. a vertically reciprocating upper needle, a looper for taking a loop of upper thread and presenting it in position below the work for the passage up therethrough' of an under needle, an oscillating curved under needle for carrying a loop of under thread up through the loop held by the looper and presenting it in position for the passage down therethrough of the upper-needle provided with a surface arranged to press the "point of the needle inward toward its axisof oscillation by engagement with the work as the needle penetrates the work. I

2. A buttonhole sewing machine having, in combination, a vertically reciprocating upper needle, a looper for takingloop of upper thread and presenting it inv position below the work for the passage up there through of an under needle, an oscillating curved under needle for carrying a loop of under thread up through the loop held by the looper and presenting it inv position for the passage down therethrough'o'f the upper needle provided with a'point having its extremity between the: inner side and the longitudinal axis of the needle. 3. A buttonhole sewing machine having, in combination, a vertically reciprocating upper needle, a -looper for taking a loop of.

upper thread and presenting ,itinto position below the work for passage .th'erethrough of an under needle, an oscillating curved under needle for vcarrying 'a loop'of under thread up through theloop held by the looper and presenting it in position for the PiISSHQe -down therethrough, of the; upper needle, and meansfor pressing the under needle inward during its passage through the work. i I

4;. A curved eye pointed under needle for.

the overscam stitch-forming mechanism of a buttonhole sewing machine, having its point located between the inner side and the longitudinal aiizis of the needle. 7

5. A curved eye pointed under needle for the overseam stitch-forming;mechanism of a buttonholesewing machine, havinginclined surfaces extending from its point'to its inner and outer sides, the rise of. the outer inclined surface being greater than that of the inner inclined surface. I

HENRY C. SEARLE. 

